The process of firing a weapon places significant amounts of wear and tear on the weapon and therefore proper cleaning and lubrication of the weapon is necessary for the safety of the shooter and longevity of the weapon. Conventional liquid lubrication performance tends to be degraded in extreme environments such as extreme cold in arctic environments and sand/dust in desert environments. In extreme cold, conventional liquid lubricants increase in viscosity which deteriorates weapon function. In desert environments, conventional liquid lubricants tend to attract and accumulate dust which leads to significant maintainability issues, excessive abrasive wear of components, and reliability issues such as weapon jamming and stoppages.
Past efforts to introduce low-friction coatings into weapon systems have failed to meet all the requirements necessary to enable liquid lubrication free operation. Treatment of sliding contact surfaces on a weapon must provide the correct combination of wear resistance, optimized coefficient of friction, corrosion resistance, as well as anti-fouling behavior in the presence of propellant residue to meet stringent military requirements. Specifically, the wear resistance of the surface treatment must be high enough to last the life of the weapon part when fired without liquid lubrication. The coefficient of friction must be low enough to enable continuous function of the weapon without liquid lubrication with the same or better characteristics such as cyclic and malfunction rate compared to the baseline oiled weapon system. The corrosion resistance of the treatment must be comparable to or better than the oiled baseline weapon over the life of the part. The anti-fouling behavior must be such that cleaning propellant residue from weapon components is the same or easier than the oiled baseline weapon.
S. J. Shaffer and M. J. Rogers, discloses lab scale studies of commercial coatings for use in small arms. The study included lab scale analysis at ambient and elevated temperatures focused on friction and wear behavior of nickel based coatings, molybdenum disulfide and resin bonded polytetrafluoroethylene (e.g. Teflon®) based materials, among others. In addition there is no disclosure of the extreme low temperature performance, corrosion performance, abrasive friction and wear performance (e.g. in the presence of sand and dust), or anti-fouling behavior of the coatings, which are all necessary characteristics to enable reliable performance in weapon systems.
Thus, a need exists for a weapon having its operating components treated in a manner that improves corrosion, abrasion and wear performance under extreme environmental conditions without the need for lubricants.
The solid lubricant coating described herein enables lubrication free operation of a firing weapon in the relevant environment with the appropriate combination of mechanical properties, wear resistance, coefficient of friction, corrosion resistance, anti-fouling behavior, and mass transport behaviors in the presence of residue and debris for operation in temperatures ranging from −65° F. to 750° F.